Signs & Symptoms of Parkinson's Disease

Signs & Symptoms of Parkinson's Disease

SIGNS & SYMPTOMS OF PARKINSON'S DISEASE: Rigidity, tremors, apathy?

When most people think of Parkinson's disease, they think of its physical symptoms, including tremors and difficulty moving. However, the disorder can also take a toll on mental health, with up to half of Parkinson's patients developing depression, according to the National Institutes of Health.

Although no medications target the underlying processes of Parkinson's, researchers are attempting to better understand the disease's mental effects in hopes of creating better treatments for them. One such team at the University of Florida's Movement Disorders Center found that the depression of Parkinson's patients can look quite different from depression experienced by otherwise healthy people, or even people with other movement disorders. In an article published in Neurology in July, 2006, Lindsey Kirsch-Darrow and her colleagues at the University of Florida reported that close to 30 percent of those with Parkinson's disease showed a pattern of mental symptoms better described as "apathy" than "depression."

"With apathy, there aren't the feelings of worthlessness or guilt you have in depression sometimes," said Kirsch-Darrow. According to paper co-author Dawn Bowers, PhD, a University of Florida clinical and neuropsychology professor, Parkinson's patients with apathy show a general lack of motivation and, instead of feeling sad, experience no mood. What's more, Parkinson's patients' lack of interest in things such as physical therapy can decrease their ability to manage their symptoms, put a strain on those who take care of them, and also influence their relationship with physicians and other healthcare providers.

While current treatments for depression—including cognitive-behavioral therapy and selective serotonin reuptake inhibitors (SSRIs)—are fairly effective for people with Parkinson's, they may not adequately address the symptoms of apathy, said Bowers.

Pure apathy

To better understand apathy, Kirsch-Darrow and her colleagues compared the mental state of people with Parkinson's with that of people with dystonia, another movement disorder. Both groups of patients experienced symptoms including rigidity, and so the two groups had a similar experience of disability.The researchers recruited 80 Parkinson's patients and 20 dystonia patients during routine medical examinations at a movement disorders clinic. The participants then completed the Beck Depression Inventory and the Apathy Evaluation Scale. Typical items on the depression questionnaire include "I feel I have failed more than the average person" and "I feel sad." The apathy evaluation asked participants, for example, whether they "are interested in learning new things" and "feel neither happy nor sad, just in between."

About half of the people with Parkinson's disorder showed the symptoms of apathy, compared with 20 percent of people with dystonia. What's more, 29 percent of people with Parkinson's had "pure apathy"—that is, apathy without depression—but none of the people with dystonia did.

Treatment Horizons

"This study shows that it's important to screen for both apathy and depression so patients can be treated appropriately," said Kirsch-Darrow. "It [is also] important to educate family members and caregivers to help them understand that apathy is a characteristic of Parkinson's disease. Apathetic behavior is not something the patient can voluntarily control, and it is not laziness or the patient trying to be difficult—it is a symptom of Parkinson's disesase," she said.

The study authors note that while there are well-established pharmacologic and psychotherapeutic treatments for depression, treatments for apathy in neurologic disorders are currently in development. In the meantime, helping patients to feel hopeful about their lives and encouraging them to re-engage with the activities they used to enjoy is important.

"Treating the mental symptoms of Parkinson's is critical to improving quality of life," says Bowers. "It is just as critical as treating their physical ones."